@misc{indiciae63435f526e8c,
  title = {Principles of comparative physiology / Principles of comparative physiology. : [Supplementary material in Charles Darwin's copy] — Illustration, Page 81},
  year = {1854},
  url = {https://www.biodiversitylibrary.org/page/34067941},
  note = {Source identifier: page-34067941}
}